To study the interaction between N-(tert-butoxycarbonyl) glycine and 2-Moprholinoethyl isocyanide in Methanol-D4 by NMR spectroscopy.
Procedure
One molar methanol-D4 solutions of 2-morpholinoethyl isocyanide (105uL, 1mmol) and Boc-Gly-OH(175mg, 1mmol) in CD3OD are prepared in separate 1 dram vials. 800uL of the solutions are used to obtain initial NMR spectra. Then 400uL of each solution is transfered to a clean nmr tube and shaken vigorously for a few seconds, the reaction is monitored by NMR spectra.
Results
Boc-Gly-OH 1H NMR 13C NMR 2-Morpholinoethyl isocyanide (MEIC) 1H NMRCH2 - 3.68 ppm (t) 4H, J=4.74Hz; CH2 - 3.60 ppm(tt) 2H, J big=6.35Hz, J small=1.95Hz; CH2 - 2.65 ppm (tt) 2H,J big=6.35Hz, J small=2.2Hz; CH2 - 2.51ppm (distorted t) 4H,J=4.64Hz with peak integrations of 2:1:1:2; Solvent peaks at 4.78 ppm (s) and 3.30 ppm (quintet).
13C NMR [triplet peaks:156.6 ppm J=24Hz and another triplet peak at 40.0 ppm J=26Hz]
Overlay1: Includes an overlay of the 1H NMRs of Boc-Gly-OH, 2-Morpholinoethyl isocyanide and few selected 49A 1H NMRs. Overlay2: Includes an overlay of 13C NMRs of Boc-Gly-OH , 2- Morpholinoethyl isocyanide and the 65min, and 23h 14min 13C NMRs of 49A.
Discussion
The 65 minute C NMR shows that the isonitrile triplet near 157 ppm is gone, indicating that the isonitrile is consumed by this time. Overlays 1 and 2 show the formation of intractable multiple products over the 23 hour period. This is unexpected since 2-morpholinoethyl isonitrile has been used successfully in at least one Ugi reaction. (Harriman 1997)
One possible explanation for the special reactivity of this particular isonitrile is the reported cyclization to a spiro type quaternary ammonium compound upon reaction with p-toluenesulfonic or hydrochloric acid (Polyakov 1983). Benzyl isonitrile does not react in this way (EXP050)
Conclusion
It does not appear that 2-morpholinoethyl isonitrile is compatible with the reaction conditions for our Ugi reactions.
Objective
To study the interaction between N-(tert-butoxycarbonyl) glycine and 2-Moprholinoethyl isocyanide in Methanol-D4 by NMR spectroscopy.Procedure
One molar methanol-D4 solutions of 2-morpholinoethyl isocyanide (105uL, 1mmol) and Boc-Gly-OH(175mg, 1mmol) in CD3OD are prepared in separate 1 dram vials. 800uL of the solutions are used to obtain initial NMR spectra. Then 400uL of each solution is transfered to a clean nmr tube and shaken vigorously for a few seconds, the reaction is monitored by NMR spectra.Results
Boc-Gly-OH1H NMR
13C NMR
2-Morpholinoethyl isocyanide (MEIC)
1H NMRCH2 - 3.68 ppm (t) 4H, J=4.74Hz; CH2 - 3.60 ppm(tt) 2H, J big=6.35Hz, J small=1.95Hz; CH2 - 2.65 ppm (tt) 2H,J big=6.35Hz, J small=2.2Hz; CH2 - 2.51ppm (distorted t) 4H,J=4.64Hz with peak integrations of 2:1:1:2; Solvent peaks at 4.78 ppm (s) and 3.30 ppm (quintet).
13C NMR [triplet peaks:156.6 ppm J=24Hz and another triplet peak at 40.0 ppm J=26Hz]
49A (Boc-Gly-OH + MEIC)
t = 02min
t = 04min
t = 08min
t = 20min
t = 24min
t = 28min
t = 33min
t = 65min [13CNMR]
t = 76min
t = 79min
t = 119min
t = 138min
t = 168min [13CNMR]
t = 190min
t = 223min [13CNMR]
t = 240min
t = 274min
t = 286min
t = 19h 53min [13CNMR]
t = 23h 14min
Overlay1: Includes an overlay of the 1H NMRs of Boc-Gly-OH, 2-Morpholinoethyl isocyanide and few selected 49A 1H NMRs.
Overlay2: Includes an overlay of 13C NMRs of Boc-Gly-OH , 2- Morpholinoethyl isocyanide and the 65min, and 23h 14min 13C NMRs of 49A.
Discussion
Conclusion
It does not appear that 2-morpholinoethyl isonitrile is compatible with the reaction conditions for our Ugi reactions.Log
2007-01-13
17:00 - Obtained a 1H NMR and a 13C NMR of 2-morpholinoethyl isocyanide and Boc-Gly-OH in methanol-d4.18:14 - Added Boc-Gly-OH solution to 2-morpholinoethyl isocyanide solution and obtained an HMR.
18:16 - Obtained 1H NMR (t = 02min)
18:18 - Obtained 1H NMR (t = 04min)
18:22 - Obtained 1H NMR (t = 08min)
18:34 - Obtained 1H NMR (t = 20min)
18:38 - Obtained 1H NMR (t = 24min)
18:42 - Obtained 1H NMR (t = 28min)
18:47 - Obtained 1H NMR (t = 33min)
19:19 - Obtained 13C NMR (t = 65min)
19:30 - Obtained 1H NMR (t = 76min)
19:33 - Obtained 1H NMR (t = 79min)
20:13 - Obtained 1H NMR (t = 119min)
20:32 - Obtained 1H NMR (t = 138min)
21:02 - Obtained 13C NMR (t = 168min)
21:24 - Obtained 1H NMR (t = 190min)
21:57 - Obtained 13C NMR (t = 223min)
22:14 - Obtained 1H NMR (t = 240min)
22:48 - Obtained 1H NMR (t = 274min)
22:56 - Obtained 1H NMR (t = 286min)
2007-01-14
14:07 - Obtained 13C NMR (t = 19h 53min)17:28 - Obtained 1H NMR (t = 23h 14min)
Tags
2-morpholin ethyl isocyanideInChI=1/C7H12N2O/c1-8-2-3-9-4-6-10-7-5-9/h2-7H2Boc-Gly-OH InChI=1/C7H13NO4/c1-7(2,3)12-6(11)8-4-5(9)10/h4H2,1-3H3,(H,8,11)(H,9,10)